【摘要】 对８个抗病毒病大豆品种的抗病力和３个大豆花叶病毒毒株致病力的变化进行了研究。结果表明：大豆品种的抗病性因连年种植逐渐退化，不同品种退化程度不一致。山东７９１９和辽用—５０１７退化较慢。３个大豆花叶病毒毒株致病力变化也不一致，弱毒株（４—２）变化小．强毒株（５—１）变化大，但多呈增强趋势。活体保存的毒株致病力均增强，引起的产量损失较大。更多还原

【Abstract】 Resistibilities of 8 soybean varieties (lines) and infecting Potentials of 3 isolates of Soybean Mosaic Virus (SMV) were studied. The results indicated that the resistibilities of 8 soybean varieties (lines) by successive planting for 4 years were degenerative, whilethat of Ludou 4 and Liao 81-5017 were degenerative slowly. Infecting potentials of 3 SMVisolates which propagating in plant all strengthen, and that of the strength isolate(5-1) developed evidently than that of weak one (4-2). The yield of soybean plants infected bySMV isolates by propagating in plants lost more.than by dry store.更多还原